As the requirement for more sophisticated labelling grows such as for use with the high speed labelling machine illustrated in U.S. patent application Ser. No. 830,118 now U.S. Pat. No. 4,183,779, the limitations of the prior art automatic labellers with respect to their ability to place the labels with the speed and precision desired and to provide the desired durability in use have become more apparent. Such prior art automatic labellers dispense self-adhesive die cut labels mounted on a carrier web which is drawn from a supply and passed sharply around the smooth end of a peeling surface or splitter tongue which causes the labels to separate from the carrier web. The carrier web is then drawn backwards by a take up e.g. is drawn around a capstan and gripped between the capstan and a pressure roller. The rotation of the capstan effects feed of the labels which move forwardly of the peeling surface while the carrier web is delivered to a take up reel.
The take up or capstan is normally driven either through a friction clutch mechanism or alternatively a particle clutch/brake mechanism used in conjunction with a driving motor and reduction gears. The capstan is started and stopped for each label dispensed or article labelled. The motion is necessarily an instant start/stop operation within the mechanical limitations of the clutch mechanism employed. These limitations translate into limited speed, accuracy and flexibility of label application and limited labeller life. In addition, the labels carried on the backing web are not always precisely spaced and the spacing and variations therein also effect the accuracy and flexibility of the labelling.
The present invention provides a solution to these typical problems of existing labellers.